Shuttle mission extended

Discovery to remain so astronauts can repair space station

October 30, 2007|By John Johnson Jr. | John Johnson Jr.,LOS ANGELES TIMES

NASA managers have extended the mission of space shuttle Discovery by a day so that the orbiting astronauts can take a closer look at a problem discovered during the weekend with the solar arrays powering the International Space Station.

The decision yesterday to perform what the space agency is calling "exploratory surgery" was made after spacewalking astronauts from Discovery spotted what appeared to be metal shavings inside a rotational joint that allows the solar panels to track the motion of the sun.

"When I opened the panel I saw black dust, like metallic shavings," said astronaut Daniel Tani, during an interview from space. "It was unmistakable that it should not be there."

The joint is on the right, or starboard, side of the station. Mike Suffredini, the NASA space station program manager, said the steel shavings could be from the bearings inside the joint.

Discovery had been scheduled to return to Earth Nov. 6. The joint inspection is scheduled to take place Thursday, NASA officials said after a meeting of mission planners yesterday afternoon.

To prepare for the detailed inspection of the starboard arrays, astronaut Scott Parazynski will use part of today's spacewalk to peek inside the left-side rotary joint. Seeing a properly functioning joint will perhaps help him spot problems with the right-side joint, officials said.

The starboard joint worked well when it was installed four months ago. Recently, however, it began vibrating and produced power spikes. It's now "parked," NASA said, and is available only for limited use.

The station now generates enough power without the right-side arrays, officials said, but it will eventually need them with the delivery in the future of power-draining station segments, including European and Japanese laboratories.

The main goal of today's spacewalk will be to attach a part of the station's backbone to a set of solar arrays being installed on the left side of the space station. The problem with the starboard solar arrays increases the importance of getting the new arrays hooked up and in operating shape, NASA said.

To inspect the bad joint, astronauts must remove most of the 22 thermal covers on the joint and look closely at all of the surfaces. Any repairs to the malfunctioning arrays would not take place until after Discovery leaves.